The proposal is concerned with the development of new methodology to measure mucociliary clearance from the lungs of human subjects. This methodology will be used to determine the relationship between tracheal mucociliary transport rates and the clearance of particles from the smaller airways; to determine the long-term variation of these measurements; to study the effects of drugs which affect the autonomic nervous system in healthy subjects and to study the effectiveness of the bronchodilator, metaproterenol on the clearance of secretions from persons with chronic bronchitis or emphysema.